Planetary transmissions are known in the earthmoving and trucking machine industries which offer a large number of gear ratios by utilizing a plurality of serially interconnected planetary gear sets and a plurality of clutches and brakes for effecting the individual gear steps. Some of these transmissions have a two or a three speed front section followed by a multi-speed range unit for providing four or more forward speeds and at least one speed in reverse.
One of the disadvantages of those prior transmissions with dual front splitter units is that the rotating output member thereof to the rear range unit could have a relatively high mass and/or moment of inertia. This could be vexatious during the transient conditions of a gear shift in that such mass can cause a greater than desired variation in the energy absorption requirements between certain shifts.
Accordingly, what is desired is a three speed front section of a power shift transmission which has load sharing between the planetary gear sets for achieving minimum inertia one of the disadvantages of prior transmissions with an input transfer gear train ahead of the transmission is the additional gear train power losses, increased cost, and the increased gear train noise generated by the transfer gear train.
The present invention is directed to overcoming one or more of the problems as set forth above.